security/tpm: make usage of PCRs configurable via Kconfig
At this moment, only GBB flags are moved from PCR-0 to PCR-1 when
vboot-compatibility is not enabled.
Change-Id: Ib3a192d902072f6f8d415c2952a36522b5bf09f9
Ticket: https://ticket.coreboot.org/issues/424
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68750
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
diff --git a/src/security/tpm/Kconfig b/src/security/tpm/Kconfig
index 8466d80..39134c1 100644
--- a/src/security/tpm/Kconfig
+++ b/src/security/tpm/Kconfig
@@ -152,4 +152,23 @@
Runtime data whitelist of cbfs filenames. Needs to be a
space delimited list
+config PCR_BOOT_MODE
+ int
+ default 0 if CHROMEOS
+ default 1
+
+config PCR_HWID
+ int
+ default 1
+
+config PCR_SRTM
+ int
+ default 2
+
+# PCR for measuring data which changes during runtime
+# e.g. CMOS, NVRAM...
+config PCR_RUNTIME_DATA
+ int
+ default 3
+
endmenu # Trusted Platform Module (tpm)
diff --git a/src/security/tpm/tspi/crtm.c b/src/security/tpm/tspi/crtm.c
index a7efcf2..36dffb8 100644
--- a/src/security/tpm/tspi/crtm.c
+++ b/src/security/tpm/tspi/crtm.c
@@ -46,7 +46,7 @@
struct region_device fmap;
if (fmap_locate_area_as_rdev("FMAP", &fmap) == 0) {
- if (tpm_measure_region(&fmap, TPM_CRTM_PCR, "FMAP: FMAP")) {
+ if (tpm_measure_region(&fmap, CONFIG_PCR_SRTM, "FMAP: FMAP")) {
printk(BIOS_ERR,
"TSPI: Couldn't measure FMAP into CRTM!\n");
return VB2_ERROR_UNKNOWN;
@@ -60,7 +60,7 @@
struct region_device bootblock_fmap;
if (fmap_locate_area_as_rdev("BOOTBLOCK", &bootblock_fmap) == 0) {
if (tpm_measure_region(&bootblock_fmap,
- TPM_CRTM_PCR,
+ CONFIG_PCR_SRTM,
"FMAP: BOOTBLOCK"))
return VB2_ERROR_UNKNOWN;
}
@@ -79,7 +79,7 @@
/* Since none of the above conditions are met let the SOC code measure the
* bootblock. This accomplishes for cases where the bootblock is treated
* in a special way (e.g. part of IFWI or located in a different CBFS). */
- if (tspi_soc_measure_bootblock(TPM_CRTM_PCR)) {
+ if (tspi_soc_measure_bootblock(CONFIG_PCR_SRTM)) {
printk(BIOS_INFO,
"TSPI: Couldn't measure bootblock into CRTM on SoC level!\n");
return VB2_ERROR_UNKNOWN;
@@ -124,7 +124,7 @@
switch (type) {
case CBFS_TYPE_MRC_CACHE:
- pcr_index = TPM_RUNTIME_DATA_PCR;
+ pcr_index = CONFIG_PCR_RUNTIME_DATA;
break;
/*
* mrc.bin is code executed on CPU, so it
@@ -134,13 +134,13 @@
case CBFS_TYPE_STAGE:
case CBFS_TYPE_SELF:
case CBFS_TYPE_FIT_PAYLOAD:
- pcr_index = TPM_CRTM_PCR;
+ pcr_index = CONFIG_PCR_SRTM;
break;
default:
if (is_runtime_data(name))
- pcr_index = TPM_RUNTIME_DATA_PCR;
+ pcr_index = CONFIG_PCR_RUNTIME_DATA;
else
- pcr_index = TPM_CRTM_PCR;
+ pcr_index = CONFIG_PCR_SRTM;
break;
}
diff --git a/src/security/tpm/tspi/crtm.h b/src/security/tpm/tspi/crtm.h
index ffa4867..2bc1d1f 100644
--- a/src/security/tpm/tspi/crtm.h
+++ b/src/security/tpm/tspi/crtm.h
@@ -8,14 +8,6 @@
#include <types.h>
#include <vb2_sha.h>
-/* CRTM */
-#define TPM_CRTM_PCR 2
-
-/* PCR for measuring data which changes during runtime
- * e.g. CMOS, NVRAM...
- */
-#define TPM_RUNTIME_DATA_PCR 3
-
#if CONFIG(TPM_LOG_CB) && CONFIG(TPM1)
# define TPM_MEASURE_ALGO VB2_HASH_SHA1
#elif CONFIG(TPM_LOG_CB) && CONFIG(TPM2)
diff --git a/src/security/vboot/vboot_logic.c b/src/security/vboot/vboot_logic.c
index a72ea87..650a420 100644
--- a/src/security/vboot/vboot_logic.c
+++ b/src/security/vboot/vboot_logic.c
@@ -184,8 +184,8 @@
static uint32_t extend_pcrs(struct vb2_context *ctx)
{
- return vboot_extend_pcr(ctx, 0, BOOT_MODE_PCR) ||
- vboot_extend_pcr(ctx, 1, HWID_DIGEST_PCR);
+ return vboot_extend_pcr(ctx, CONFIG_PCR_BOOT_MODE, BOOT_MODE_PCR) ||
+ vboot_extend_pcr(ctx, CONFIG_PCR_HWID, HWID_DIGEST_PCR);
}
#define EC_EFS_BOOT_MODE_VERIFIED_RW 0x00